It would make a nice Christmas present, but given the current state of affairs in the chip industry, I'd say it's only going to be a reality next year--unless there are some surplus yields of Broadcom and DRAM chips squirrelled away someplace.
Seriously now, I would expect mostly minor revisions until they can move to another SoC (and it's probably easier to move to a near-identical, higher-specced part right now).
What would you want to see in a new version that isn't in the 4 or other pi variants? Personally I'd like more USB3 ports, but it works for all my other needs.